A typical gas turbine includes a compressor, a combustor, and a turbine. In addition, air that is introduced from an air-intake port is compressed into high-temperature and high-pressure compressed air by a compressor. In the combustor, fuel is supplied to the compressed air and is combusted to obtain a high-temperature and high-pressure combustion gas (operation fluid). The turbine is operated by the combustion gas to drive a power generator that is connected to the turbine. The combustion gas, which is used to drive the turbine, is discharged as a flue gas on an exhaust side of the turbine.
A control device that controls the gas turbine adjusts the amount of air introduced to the compressor, a supply amount of fuel, and the like to execute temperature adjustment control of controlling an operation of the gas turbine so that a turbine inlet temperature of the turbine to which the combustion gas is introduced does not exceed an upper limit temperature that is set in advance. The reason for the execution is as follows. The higher the turbine inlet temperature is, the further the performance (work efficiency) of the gas turbine is enhanced. On the other hand, when the turbine inlet temperature is excessively high, it is difficult for a high-temperature component in the vicinity of the turbine inlet to endure a thermal load. Specifically, in the temperature adjustment control, the operation of the gas turbine is controlled so that the temperature of the flue gas discharged from the turbine does not exceed a temperature adjustment line that is the upper limit temperature of the flue gas temperature which is defined in correspondence with a gas turbine state quantity such as a load (power generator output) or a pressure ratio of a gas turbine, and the like. Here, the temperature adjustment line is defined by a mathematical function in which the greater the load of the gas turbine is, the lower the upper limit temperature of the flue gas temperature is, and the smaller the load of the gas turbine is, the higher upper limit temperature of the flue gas temperature is.
Examples of the gas turbine control device that executes the temperature adjustment control includes a control device that is described in Japanese Patent Publication No. 2008-75578 and Japanese Patent Publication No. 2007-40171. In a gas turbine operation control device described in Japanese Patent Publication No. 2008-75578, as the amount of load variation during a load increase of the gas turbine is great, an opening degree of an inlet guide vane, which is provided on an intake side of the compressor, is corrected to an open direction. In addition, in a gas turbine inlet guide vane control device described in Japanese Patent Publication No. 2007-40171 includes a flue gas temperature control unit. In the flue gas temperature control unit, a preceding IGV opening degree is set on the basis of an opening degree schedule of the inlet guide vane (IGV) which is obtained in advance. In addition, when the flue gas temperature is likely to exceed a limiting value during an operation, the preceding IGV opening degree is automatically subjected to a feedback correction to increase the IGV opening degree.
In addition, with regard to the gas turbine control device, an operation and maintenance schedule supporting system of a power generation facility is disclosed in Japanese Patent Publication No. 2002-330541 and Japanese Patent Publication No. 2002-330542. In the system in Patent Literature 3 and Patent Literature Japanese Patent Publication No. 2002-330541 and Japanese Patent Publication No. 2002-330542, plant data that is acquired is used to calculate a remaining operational lifespan of a power generation unit, and the remaining operational lifespan of the power generation unit which is calculated and a remaining operational lifespan of another power generation unit are compared with each other to change operation conditions of the power generation unit to realize high economic efficiency.